42 ideas
18951 | For scientific purposes there is a precise concept of 'true-in-L', using set theory [Putnam] |
18953 | Modern notation frees us from Aristotle's restriction of only using two class-names in premises [Putnam] |
18949 | The universal syllogism is now expressed as the transitivity of subclasses [Putnam] |
18952 | '⊃' ('if...then') is used with the definition 'Px ⊃ Qx' is short for '¬(Px & ¬Qx)' [Putnam] |
18958 | In type theory, 'x ∈ y' is well defined only if x and y are of the appropriate type [Putnam] |
18954 | Before the late 19th century logic was trivialised by not dealing with relations [Putnam] |
18956 | Asserting first-order validity implicitly involves second-order reference to classes [Putnam] |
18962 | Unfashionably, I think logic has an empirical foundation [Putnam] |
18961 | We can identify functions with certain sets - or identify sets with certain functions [Putnam] |
18955 | Having a valid form doesn't ensure truth, as it may be meaningless [Putnam] |
17518 | Counting 'coin in this box' may have coin as the unit, with 'in this box' merely as the scope [Ayers] |
17516 | If counting needs a sortal, what of things which fall under two sortals? [Ayers] |
18959 | Sets larger than the continuum should be studied in an 'if-then' spirit [Putnam] |
17520 | Events do not have natural boundaries, and we have to set them [Ayers] |
18957 | Nominalism only makes sense if it is materialist [Putnam] |
18950 | Physics is full of non-physical entities, such as space-vectors [Putnam] |
17519 | To express borderline cases of objects, you need the concept of an 'object' [Ayers] |
12132 | Indiscernibility is a necessary and sufficient condition for identity [Brody] |
17511 | Recognising continuity is separate from sortals, and must precede their use [Ayers] |
17510 | Speakers need the very general category of a thing, if they are to think about it [Ayers] |
17522 | We use sortals to classify physical objects by the nature and origin of their unity [Ayers] |
17515 | Seeing caterpillar and moth as the same needs continuity, not identity of sortal concepts [Ayers] |
15834 | Brody bases sortal essentialism on properties required throughout something's existence [Brody, by Mackie,P] |
17517 | Could the same matter have more than one form or principle of unity? [Ayers] |
17513 | If there are two objects, then 'that marble, man-shaped object' is ambiguous [Ayers] |
12140 | Modern emphasis is on properties had essentially; traditional emphasis is on sort-defining properties [Brody] |
17523 | Sortals basically apply to individuals [Ayers] |
11895 | A sortal essence is a property which once possessed always possessed [Brody, by Mackie,P] |
12141 | Maybe essential properties are those which determine a natural kind? [Brody] |
12137 | De re essentialism standardly says all possible objects identical with a have a's essential properties [Brody] |
12142 | Essentially, a has P, always had P, must have had P, and has never had a future without P [Brody] |
12143 | An object having a property essentially is equivalent to its having it necessarily [Brody] |
12144 | Essentialism is justified if the essential properties of things explain their other properties [Brody] |
12139 | Mereological essentialism says that every part that ensures the existence is essential [Brody] |
17514 | Temporal 'parts' cannot be separated or rearranged [Ayers] |
17521 | You can't have the concept of a 'stage' if you lack the concept of an object [Ayers] |
12135 | Interrupted objects have two first moments of existence, which could be two beginnings [Brody] |
17509 | Some say a 'covering concept' completes identity; others place the concept in the reference [Ayers] |
17512 | If diachronic identities need covering concepts, why not synchronic identities too? [Ayers] |
12130 | a and b share all properties; so they share being-identical-with-a; so a = b [Brody] |
12138 | Identity across possible worlds is prior to rigid designation [Brody] |
18960 | Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam] |